3.0 engine failure...

[Cyrix2k]

The X5 I fixed & sold on to a friend just had its engine blow up. He reported a tapping sound followed by the engine locking up & smoke out the exhaust. It won't turn over at all. He said he never got an oil pressure light and it sounded like tapping (top end), not knocking (bottom end). At this point we assume it needs a new engine.

As far as N52s are concerned, does anyone know what the interchange looks like? I think all 2nd gen (plastic valve cover) N52 short blocks are interchangeable and only differ in terms of what's bolted onto them, right? So an N52N from a 328i should work if we swap over all the E70 bits? Any gotchas? Also worth noting is this E70 does have adaptive drive. The interchange mentions that for some reason.

On to what I think happened. This engine previously through VANOS codes about 20k miles ago and it's always had a bit of an idle stumble when it first starts up. I replaced the VANOS "filters" (non-return valves) and found metal back then, and I replaced the VANOS solenoids with new, genuine BMW solenoids. I also found the center of the oil filter housing cap to be loose and possibly broken, so I replaced the cap with a completely new cap. The engine ran better and the codes never came back although the "stumble" / idle issue never completely went away. I understand this is common with N52s though. About 500 miles before I sold it, I replaced the VANOS filters again. This time they were perfectly clean with absolutely no indication of metal. The oil filter has always come out clean.

BMW has a recall for N51 and N52 engines produced from September 2009 to November 2011. The updated recall is here https://static.nhtsa.gov/odi/rcl/201...4V176-2716.pdf However, the original recall shows them recalling vehicles by model year - 2010 through 2012, as seen here https://static.nhtsa.gov/odi/rcl/201...4V176-3214.pdf This is a very late production 2009 X5 with a production date of September 24th 2009. It is my opinion that this vehicle should have been included as part of the recall campaign but was not. This was not an open recall on this vehicle and I don't recall seeing any documentation of this recall being performed; I did have complete records for the vehicle. We won't know for certain what happened until we tear the engine down, but the symptoms of cam bolt failure are certainly consistent with what happened and it would explain the lack of an oil pressure warning during failure. I assume at this point BMW will not stand behind this...